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The Two Stages Of Photosynthesis

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Photosynthesis is the process in which light energy from the sun is converted into organic compounds. This process fuels nearly all of the energy that supplies the living systems on earth. Autotrophs are the organisms that obtain energy through photosynthesis. Plants-autotrophs-depend on the sun for energy through photosynthesis. Humans and animals-heterotrophs-consume these plants. Heterotrophs are organisms that cannot obtain energy from photosynthesis, so they get energy from autotrophs. Photosynthesis is divided into two stages: the light reactions, where energy absorbed from the sun is converted into chemical energy, and the calvin cycle, where organic compounds form, utilizing CO2 and the energy from ATP and NADPH. Photosynthesis is divided into two stages: the light reactions and the Calvin cycle.
The light reactions are the first stage of photosynthesis. Light from the sun is absorbed by chloroplasts. Chloroplasts have a unique structure because they are enveloped by a pair of membranes; the inner membrane homes another system of membranes known as thylakoids. These thylakoids are layered and connected to form grana, which is surrounded by stroma, a solution. Chloroplasts give plants their green color because of the chlorophylls present in the membrane of the thylakoids. Though light from the sun is white, it is actually composed of an array of colors. When this white light hits an object, the colors are transmitted or absorbed by the object. Pigments absorb colors

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